This project will investigate the development of child-related factors during the first three years of life and how they predict the development of preschool social-emotional and cognitive competence in a sample of rural children in poverty. The sample includes 1400 infants and their parents located at two geographic sites; rural central Pennsylvania and rural Southeast North Carolina. Measurements of child temperamental reactivity and self-regulation will be conducted in the home by three independent methods at the ages of 6, 15, and 24 months. Methods will include (1) behavioral observations to both "challenge tasks" and naturally occurring situations that elicit negative distress and its management (both anxiety/fear and anger); (2) collection of glucocorticoid (e.g., salivary cortisol) and heart-rate variability (vagal tone), and (3) parental and observers reports of the child"s temperamental qualities (at these times as well as 36 months). In addition, at 24 and 36 months, the project will assess factors related to early executive function including attention, inhibitory control, and cognitive flexibility. At present, there are no data on the measurement and interpretation of these constructs in high-risk, rural populations. This project will interact with other projects and the Core to examine how child characteristics reciprocally interact with (1) basic developmental processes such as early language and cognitive abilities, (2) the quality of parent-child interactions, and (3) factors operating at the parenting, marital, family, and extra-familial levels to affect preschool social and cognitive readiness.